The
UTC and ISO/IEC
JTC1/SC2 (the subcommittee responsible for the maintenance of ISO/IEC 10646)
synchronize the character repertoire and code points of their
respective standards: characters are not added to one standard
without being approved for the other. While proposed characters may have been
approved by either committee, they only become part of the Unicode Standard
when a version containing them is published.

Due to the nature of its membership,
the Unicode Consortium has designed its process to be responsive to
market requirements.
The ISO standards review and approval process is by nature lengthier than the Unicode process,
involving, as it does, national standards organizations of any country
wishing to participate. In that process, a
proposal goes through the following stages before publication. The numbers for these stages
are cited in the ISO Stage column on the Proposed New
Characters (Pipeline Table) page. "WG2" refers to Working Group 2, the working group
under SC2 which handles the technical work on ISO/IEC 10646.

Initial Proposal:
A proposal document has been submitted to WG2 and is included
in the formal document record. The proposal may not yet have
been taken up on the agenda of a WG2 meeting, or may have
had been included pro forma on an agenda, where it is simply
raised FYI to the attention of national bodies, inviting them
to review and provide feedback on the proposal.

Provisional acceptance by WG2:
A proposal has been technically reviewed by WG2, with feedback
from one or more national bodies and liaison organizations such as the Unicode
Consortium, and a consensus has been
reached within WG2 that a character, group of characters, or
a repertoire for a script should be encoded. However, a
final resolution specifying code positions and character names
may not yet have been taken or approval may be postponed
pending further feedback from national bodies regarding one
or more technical issues in the proposal. (In recent times, this
stage has seldom been used by WG2.)

Final acceptance by WG2 - in Bucket:
WG2 has decided to specify code
positions and character names for addition to the standard,
but without necessarily determining which amendment they
should be included in for formal balloting. This status is
referred to as "being in the bucket," a holding category
waiting for an appropriate amendment. This stage is
transitional and typically is only used when WG2 has a meeting
that does not authorize a formal amendment to 10646.

Hold for Committee Ballot:
WG2 has decided to specify exactly
which of any characters approved and "in the bucket" are to
be balloted in an amendment to 10646. Note that in current
practice, most character approvals move directly from Stage 1
to Stage 4, for efficiency, unless there is some technical
issue with them or unless WG2 decides that it needs to wait
before starting to progress a new amendment.

Committee Ballot: This stage comprises one or more formal committee
ballots by the member bodies of the WG2 parent committee, SC2. During
each ballot, member bodies and liaison organizations (such as the
Unicode Consortium) review the collection of characters and scripts
in the ballot document and provide technical and editorial feedback.
After each ballot is completed, the editor resolves the comments.
This stage can take a year to two years, depending on the schedule
of ballots and of WG2 meetings. Technical changes to the approved characters
may still occur as part of this process, including the addition of characters that
were not originally on the ballot.
This stage begins as soon as the SC2 Secretariat has
issued the formal amendment ballot. In this ballot phase
the committee draft is known as a PDAM (Proposed Draft Amendment).
After resolution of PDAM ballot comments by the editor, WG2 may decide to issue an
additional committee ballot, or if the ballot seems mature, move on to the next
ballot stage.

Enquiry Ballot: SC2 has submitted
the DAM (Draft Amendment) for approval by the national bodies
at the JTC1 level. During this stage, there may still be technical changes to the ballot
text, although every effort is made to resolve technical issues during the committee ballot(s),
before an enquiry ballot is issued. This is a five month ballot.

Approval Ballot: SC2 has submitted
the FDAM (Final Draft Amendment) for approval by the national bodies at the JTC1 level.
At this stage, which is largely pro forma, there are no further technical changes to
the ballot text. This is a two month ballot.
The issuance of the
FDAM ballot is the point at which Unicode implementers can feel
secure in implementing the corresponding, synchronized
repertoire in the Unicode Standard. When the FDAM ballot is
approved, JTC1 considers the amendment fully approved,
awaiting publication.

ITTF Publication:
An approved amendment to 10646 is submitted to ITTF for formal
publication. An amendment to a standard (or the standard
itself) is not actually considered an International Standard
until ITTF has completed publication. Depending on the
complexity of the standard and any editing issues which
may turn up, this may take several months to more than a
year from the completion of the FDAM ballot.

Note: Sometimes final ISO approval of new characters can occur a long time
after they have been approved by the UTC. Conversely, in some instances a character or group of
characters may reach Stage 4 or even Stage 5 or Stage 6 in the ISO
process before they have been formally considered for
approval by the UTC. During the period when the ISO process is not complete and
when the UTC may still be in the process of synchronizing
character approvals, use of proposed characters is at an
implementer's own risk. The repertoire and allocation of the
characters may change before they are published in a particular
version of the Unicode Standard.